1. Field of Invention
The present invention is generally related to modems, and more particularly to modems supporting multi-tone multi-band modulation protocols.
2. Description of the Related Art
Digital Subscriber Lines (DSL) technology and improvements thereon including: G.Lite, ADSL, VDSL, HDSL all of which are broadly identified as X-DSL have been developed to increase the effective bandwidth of existing subscriber line connections, without requiring the installation of new fiber optic cable. An X-DSL modem operates at frequencies higher than the voiceband frequencies, thus an X-DSL modem may operate simultaneously with a voiceband modem or a telephone conversation.
Currently there are over ten discrete X-DSL standards, including: G.Lite, ADSL, VDSL, SDSL, MDSL, RADSL, HDSL, etc. XDSL modems are typically installed in pairs, with one of the modems installed in a home and the other in the telephone companies central office (CO) switching office servicing that home. This provides a direct dedicated connection to the home from a line card at the central office on which the modem is implemented through the subscriber line or local loop.
What is needed is scalable modem architecture that allows a more flexible hardware response to the evolving X-DSL standards and the problems associated with providing hardware to handle each new standard.